This invention generally relates to an apparatus for molding formable materials and its method of operation. More particularly, the invention relates to a food molding apparatus and method of forming food products wherein precise portions of a formable material are produced in a desired shape, with the machine allowing increased capacity by enabling the width of the machine to be increased significantly.
In the area of large scale food processing, forming food products of formable materials such as ground beef, whole muscle chicken products, dough or other food mixtures, is critical to further processing procedures, such as cooking or frying of large volumes of food products. Fast food chains are well-known for the use of these types of products, which are also utilized by restaurants and individual consumers. In the automated production of molded and portioned food products, high-speed machinery is used to form a patty or similar product. Particular problems in such machinery have been found in attempting to increase production efficiency while providing uniform product shapes and weights.
In known food forming machines, a food supply hopper is charged with an amount of ground beef or the like, which is forced under high pressure through one or more discharge openings or slots formed in the supply hopper. A mold plate having mold cavities corresponding to the discharge openings in the supply hopper is moved between a fill position where the formable food product is forced into the cavities under pressure, and a knock-out position where the contents of the cavity are removed or knocked out. This cycle is repeated as quickly as possible to increase capacity of the machine. In many such machines, an end feed conveyor system is positioned relative to the knock-out position of the mold plate to receive the molded food products and transport them for further processing.
Substantial limitations in the known molding machines have been found, based upon the structural integrity of the mold plate and supply hopper, which are critical due to the high pressures used to fill the mold cavities in the mold plate. Deflection of the mold plate, the support structure for the mold plate and/or the supply hopper can create leakage of the formable material, causing significant problems in producing uniform formed products of precise weight and shape. Such leakage of the formable material also results in significant operational problems in use of the machine. Preventing deflection of the members has required heavy-duty construction, and has limited the widths of these members in the machine. In addition, the thicknesses of the members is limited due to limitations regarding how far a product be dropped from the cavity of the mold plate onto a conveyor for example. It should also be recognized that a conveyor system would have to be spaced from the machine a distance to accommodate any food product to be carried thereby, limiting the total thickness of the reacting support plate and therefore imposing limitations on the width to prevent deflection of these members. Known high-speed molding machines are therefore limited to a twenty-six inch conveyor belt width, corresponding to the width of the mold plate and supporting structure. These same aspects therefore limit the number of cavities which can be formed in the mold plate across its width, and therefore limit the capacity of such machines.
Another significant problem in conventional food forming apparatus is found in that the pressure applied to the food product to fill the mold cavities of the mold plate is normally applied while the mold plate is moving from the fill to knock-out positions. To increase speed of operation, continuous movement of the mold plate or only short duration stoppage for ejecting product from the mold cavities is common. Movement of the mold plate under filling pressure causes leakage of the food product. Additionally, pressure used during filling of the mold cavities continues to be applied even after movement of the mold plate withdraws the cavities from exposure to the food material, causing food product to be forced back against the pressurizing force being applied, further damaging the material. With food products such as whole muscle chicken products or the like, these forces on the meat product within the supply hopper and relative to the mold plate cause significant degradation of the food product, particularly with chicken products where the whole muscle quality of the meat should be maintained.
In addition to the limitations described above, known forming machines generally do not have the ability to utilize a flow-through type of conveyor system, limiting their use with respect to other processing equipment, as well as limiting their use as a forming machine. It would therefore be desirable to provide a forming machine to overcome these limitations to increase capacity of the machine, while handling the formable material gently so as to maintain the integrity of the material.